Rotating assembly, in particular for guiding a motor vehicle wheel

Abstract

A motor vehicle drive wheel assembly comprising a fixed subassembly comprising two outer raceways; and, a rotating subassembly comprising a first inner race, a second inner race and two rows of balls arranged in two pitch planes PP1 and PP2. The second inner bearing race has an outer diameter, measured in a section plane perpendicular to the axis of rotation and located between the first pitch plane and the second pitch plane, at a measurement distance DM of the first pitch plane, which is greater than a given threshold value VS.

The invention claimed is: 
     
       1. A rotating assembly, comprising:
 an outer subassembly comprising a first annular outer raceway and a second annular outer raceway centered on a common axis of rotation; 
 an inner subassembly comprising a first inner bearing race on which a first inner raceway is formed, the first inner raceway having a raceway bottom diameter DI 1 , and a second inner bearing race on which a second inner raceway is formed, the second inner raceway having a raceway bottom diameter DI 2  larger than the raceway bottom diameter DI 1  of the first inner raceway, the second inner bearing race and the first inner bearing race being fixed relative to each other; and 
 balls forming a first row of balls capable of rolling on the first outer raceway and the first inner raceway and a second row of balls capable of rolling on the second outer raceway and the second inner raceway for guiding the outer subassembly and the inner subassembly relative to each other in rotation about the axis of rotation, the balls of the first row of balls having a diameter DC 1 , a first pitch plane containing the centers of the balls of the first row of balls being located at a non-zero distance L from a second pitch plane containing the centers of the balls of the second row of balls; wherein 
 the second inner bearing race has an outer diameter, measured in a section plane perpendicular to the axis of rotation and located between the first pitch plane and the second pitch plane, at a measurement distance DM from the first pitch plane, which is greater than a given threshold value VS, where: 
 
       
         
           
             
               { 
               
                 
                   
                     
                       
                         DM 
                         = 
                         
                           1.25 
                           ⨯ 
                           
                             
                               DC 
                               ⁢ 
                               1 
                             
                             2 
                           
                         
                       
                     
                   
                   
                     
                       
                         VS 
                         = 
                         
                           sup 
                           ⁡ 
                           ( 
                           
                             
                               
                                 1.1 
                                 ⨯ 
                                 DI 
                               
                               ⁢ 
                               1 
                             
                             ; 
                             
                               
                                 DI 
                                 ⁢ 
                                 1 
                               
                               + 
                               
                                 
                                   DC 
                                   ⁢ 
                                   1 
                                 
                                 2 
                               
                             
                           
                           ) 
                         
                       
                     
                   
                 
                 . 
               
             
           
         
       
     
     
       2. The rotating assembly of  claim 1 , wherein the second inner bearing race comprises an axial end face facing axially toward the first pitch plane, and axially bearing against a bearing face of the first inner bearing race, the axial end face being positioned in a transverse plane situated between the first pitch plane and the second pitch plane, at a distance D from the first pitch plane that is less than half the diameter DC 1  of the balls of the first row of balls. 
     
     
       3. The rotating assembly of  claim 1 , further comprising a first one-piece bearing cage, the first one-piece bearing cage comprising a ring defining a reference axis of the first bearing cage and retaining claws distributed around the periphery of the ring to delimit cells for housing the balls of the first row of balls. 
     
     
       4. The rotating assembly of  claim 3 , wherein the ring is positioned on one side of the first pitch plane opposite the second pitch plane, the retaining claws projecting from the ring in the direction of the second pitch plane by crossing the first pitch plane, the retaining claws having a free distal end, the cells each being delimited by two adjacent retaining claws among the retaining claws of the first one-piece cage and by a portion of the ring connecting the two adjacent retaining claws. 
     
     
       5. The rotating assembly of  claim 4 , wherein for each of the cells, the two adjacent retaining claws each comprise a concave retaining guide facet facing the ball housed in the cell. 
     
     
       6. The rotating assembly of  claim 5 , wherein the retaining guide facets are located at least partially inside a first pitch cylinder, wherein a base of the first pitch cylinder is a first pitch circle passing through the centers of the balls of the first row of balls and centered on the axis of rotation. 
     
     
       7. The rotating assembly of  claim 6 , wherein for each of the cells, the ring portion connecting the two adjacent retaining claws comprises an end guide facet facing the ball housed in the cell, the end guide facet being located at least partially radially outside the first pitch cylinder. 
     
     
       8. The rotating assembly of  claim 6 , wherein the retaining guide facets lie at least partially between the first pitch plane and the second pitch plane. 
     
     
       9. The rotating assembly of  claim 6 , wherein the first bearing cage further comprises additional claws distributed around the periphery of the ring, each of the additional claws being associated with one of the retaining claws and having a free distal end located radially outside and opposite the associated retaining claw and wherein for each of the cells, two additional claws of the additional claws are associated with the two adjacent retaining claws, and the two additional claws each comprise an additional concave guide facet facing the ball housed in the cell, the additional guide facets being located at least partially outside the first pitch cylinder and at least partially between the first pitch plane and the second pitch plane. 
     
     
       10. The rotating assembly of  claim 6 , wherein for each of the cells, the two adjacent retaining claws each comprise an additional concave guide facet facing the ball housed in the cell, the additional guide facets being located at least partially outside the first pitch cylinder and at least partially between the first pitch plane and the second pitch plane. 
     
     
       11. The rotating assembly of  claim 4 , wherein the first bearing cage further comprises additional claws distributed around the periphery of the ring, each of the additional claws being associated with one of the retaining claws and having a free distal end located radially outside and opposite the associated retaining claw. 
     
     
       12. The rotating assembly of  claim 3 , wherein the ring of the first bearing cage further comprises a planar annular stacking face axially facing away from the retaining claws, and a centering bearing having a symmetry of revolution about the reference axis of the first bearing cage, the first bearing cage further comprising planar facets facing axially away from the annular stacking face, and centering facets, turned radially opposite the centering bearing, wherein, viewed in orthogonal projection on a stacking plane containing the planar annular stacking face, the planar facets and the planar annular stacking face are superimposed, and the centering facets face the centering bearing. 
     
     
       13. The rotating assembly of  claim 1 , further comprising a second one-piece bearing cage, comprising a ring defining a reference axis of the second bearing cage and retaining claws distributed around the periphery of the ring of the second bearing cage to delimit the cells for housing the balls of the second row of balls, the ring of the second bearing cage being positioned on a side of the second pitch plane opposite the first pitch plane, the retaining claws of the second bearing cage protruding from the ring of the second bearing cage toward the first pitch plane crossing the second pitch plane, the retaining claws of the second bearing cage having a free distal end, each the cells being delimited by two adjacent retaining claws among the retaining claws of the second bearing cage and by a portion of the ring connecting the two adjacent retaining claws. 
     
     
       14. The rotating assembly of  claim 1 , wherein the ball diameter DC 1  of the first row of balls is less than or equal to a ball diameter of the balls forming the second row of balls. 
     
     
       15. The rotating assembly of  claim 1 , wherein the second inner bearing race is shrunk on a shrink-fit bearing of the first inner bearing race. 
     
     
       16. The rotating assembly of  claim 1 , wherein the outer subassembly constitutes a fixed subassembly of a motor vehicle drive wheel guide, and the inner subassembly constitutes a rotating subassembly of the motor vehicle drive wheel guide, capable of rotating with respect to the fixed subassembly about the axis of rotation, the rotating subassembly comprising a wheel hub comprising a flange provided with an interface for attaching a wheel rim or a brake disc, the flange forming a mounting face of the wheel rim or of the brake disc facing axially in a direction of disassembly of the wheel rim or of the brake disc, the direction of disassembly being parallel to the axis of rotation, the first inner bearing race being constituted by the wheel hub or shrunk on the wheel hub, the second inner bearing race being shrunk on a shrink-fit bearing of the wheel hub. 
     
     
       17. The rotating assembly of  claim 16 , wherein the rotating subassembly further comprises a transmission bowl, the inner bearing race bearing against the transmission bowl at an annular contact interface extending at least in a radial direction relative to the axis of rotation. 
     
     
       18. The rotating assembly of  claim 17 , wherein the annular contact interface is positioned at least partially, between the first pitch plane and the second pitch plane. 
     
     
       19. The rotating assembly of  claim 17 , wherein the annular contact interface is positioned completely between the first pitch plane and the second pitch plane. 
     
     
       20. The rotating assembly of  claim 16 , wherein the wheel hub is a solid one-piece metal part.